Predictions of conditional moment closure for nonpremixed combustion in a statistically stationary homogeneous isotropic turbulence are tested against direct numerical simulation values. Numerical experiments are carried out for Taylor microscale Reynolds number of 49 and 66. Chemical reaction is modeled by a single and multi-step mechanisms. Turbulent mixing is modeled by two different methods. CMC predictions of a major species mass fraction are found to be accurate if the modeled value of total scalar dissipation rate is accurate. However, error estimates indicate that accurate predictions of intermediate species consumed by the fastest reaction, may require a second order closure in CMC.